Research On Mixed-model Assembly Line Banlance Problem Under Uncertainty

How to put the personalized needs of customers and the economic advantages of bulk together is an unavoidable problem the manufacturer has to face. Scale production way is mainly rely on diminishing marginal costs and gain a competitive advantage; However, as the individuation and diversification the consumers demand gradually need, the products which are mass but single and fixed cannot meet the needs of consumers.Mixed-mode assembly line provides a train of thought to solve this problem. Mixed-mode assembly line can be under the condition of without increasing the product inventory to meet the diversification of user’s requirements, improve the production efficiency, reduce the enterprise cost, balance material consumption rate and load, enhance the flexibility and adaptability of production line, improve the enterprise ability of fast react to the market environment changes, realize the requirement of product the needed production at the needed amount at the right time.On the basis of assembly line balancing problem of the Mixed-mode at home and abroad, this paper points out the shortages of the present study which assuming that some information is determined. But often there are a lot of uncertainty factors in the actual assembly process, demand uncertainty, the product proportion uncertainty and operation time uncertainty, the machine fault uncertainty, maintenance time uncertainty, and so on, these uncertain factors lead to the assembly line lose balance, and make the assembly efficiency of the wasted effort.The system research about Mixed-mode assembly line balancing problem under uncertainty must be carried on. According to the source of uncertainty, there are internal uncertainty and external uncertainty. Taking the demand uncertainty, the product proportion uncertainty and operation time uncertainty, machine failure frequency uncertainty and maintenance time uncertainty into account of the influence of the Mixed-mode assembly line balancing, according to these uncertainty factors on the influence of the Mixed-mode assembly line balancing, turn the influence on Mixed-mode assembly line of demand uncertainty, and the operation time uncertainty into the influence of the operation time, and turn the influence of the uncertainty of machine out of order number and uncertainty of maintenance time into the influence on the workstation availability, then use computer simulation method to deal with uncertainty.Built type Ⅰ balance which means the minimum number of workstations, type Ⅱ balance which minimize the beat, type SI balance which is to minimize the equilibrium index of the mathematical model and design algorithm based on genetic algorithm,according to the balanced goal. Coding when consider Precedence relation constraints of elements, adopt the way of real number encoding; Design different ways of decoding for different balanced goals; Choose operator by the traditional way of roulette; Crossover operator use single-point crossover approach; Mutation operator use random coding approach. Through solving the traditional assembly line balancing problem Thomopoulos problem as an example, this article verify the effectiveness of the algorithm.Research Mixed-mode assembly line under uncertainty,and taking HT group automobile assembly line in QJ city as an example,class Ⅰ, class Ⅱ and class SI balance of auto assembly line under the uncertainty are studied. By comparing find that the efficiency of the assembly line are significantly enhanced, thus further proves the application value of this article.